Bubble gum compositions generally contain a water insoluble gum base (either natural rubber, synthetic rubber, or mixtures thereof), a water-soluble flavor, and water soluble sweeteners such as sucrose and corn syrup, or in a sugarless gum, sorbitol, mannitol and artificial sweeteners. Also incorporated within the gum base may be plasticizers to improve the film forming ability, consistency and texture of the gum.
Synthetic rubber gum bases have found extensive use in bubble gum formulations. In particular, the elastomer styrene-butadiene copolymer (SBR) has been used and has required the use of accompanying ester gums (glycerol esters of rosin) in order to effect compatibilization with other chewing gum base components, and in order to achieve desired film-forming properties for the bubble gum. Bubble gum bases made by use of SBR and ester gums characteristically are rigid, difficult to chew and require a significant amount of energy as well as the addition of extensive amounts of softeners, fillers, etc. to achieve the proper texture for use in a chewing gum.
Another synthetic rubber, polyisobutylene elastomer (PIB), has been used in bubble gum formulations but the art has considered it necessary to include certain accompanying ingredients to effect compatibilization with other components of the PIB-containing gum base. For example, U.S. Pat. No. 3,984,574 to Comollo discloses a gum base which includes polyisobutylene in combination with polyvinyl acetate but which also requires additional components such as hydrogenated or partially hydrogenated vegetable oils or animal fats in an amount of 5-50%, and filler (mineral adjuvants) in an amount of 5-40%, in order to achieve a non-tacky base. It is also disclosed that other elastomers may be employed in place of or together with the polyisobutylene, namely, polyisoprene, a copolymer of isobutylene and isoprene, or the copolymer of butadiene and styrene, but the amounts are not disclosed. In addition, polyvinyl acetate having a molecular weight of at least 2,000 is used in amounts up to 55%.
Cherukuri et al. in U.S. Pat. No. 4,352,822 discloses the use of polyisobutylene elastomers to make a bubble gum having film forming characteristics. The elastomer gum base used a combination of essential ingredients including glyceryl triacetate and acetylated monoglyceride as plasticizers, a polyterpine resin as an anti-tack agent, polyethylene wax and various other conventional chewing gum additives. A hydrophilic-type detackifier is disclosed to be used in amounts of 5 to 60%. This agent absorbs saliva and become slippery when the gum is chewed. An example of a detackifier is a vinyl polymer, such as polyvinyl acetate, polyvinyl butyl ester and copolymers of vinyl esters and vinyl ethers having a molecular weight from about 2,000 to about 10,000. Cherukuri et al. does not disclose incorporating SBR in the gum.
The prior art has recognized that it is possible to blend elastomers in a single bubble gum base and to blend bubble gum bases having similar compositions to obtain different textural characteristics. However, it is not known to blend bubble gum bases of dissimilar functional ingredients to achieve a textural advantage. That is, it is not known to combine one gum base, comprising an elastomer together with accompanying coingredients necessary or desired to improve the characteristics of that elastomer, with a second gum base, comprising a different elastomer together with its accompanying ingredients. The "accompanying ingredients", being compatible with one elastomer or the other and being selected to adapt properties to that elastomer, would be expected to be superfluous or even deleterious to the other elastomer or to any proposed combination thereof.
In addition, the ingredients present in a gum base contribute to film formation (and bubble formation) via a mechanism of coaction specific to that group of ingredients. Blending in a different gum base would be expected to disrupt both gum bases' mechanisms and prevent effective film/bubble formation.
For instance, PIB gum base uses polyisobutylene elastomer and plasticized, high molecular weight polyvinyl acetate as the film former. SBR gum base uses styrene butadiene elastomer in combination with an ester gum resin as the film former to achieve a textural or processing advantage. The SBR bubble gum base achieves good bubble formation at low cost but has the disadvantage of a hard chew initially. The PIB bubble gum base achieves superior bubble quality and compared to an SBR bubble gum base, a soft initial chew but at a higher cost.
Also, it is known that an SBR base bubble gum can be difficult to process in the plant under normal production techniques. The gum is sticky, stringy and too elastic. At times this results in difficulty in obtaining a final product. Thus far it is not known that anyone has suggested co-blending a PIB base into the gum to improve the processing conditions.
It would be highly desirable to improve the bubble quality and initial chew properties of an SBR base bubble gum formulation in an inexpensive and simple manner.
It would also be desirable to achieve the same bubble quality and chew properties of a PIB base bubble gum but at a lower cost.
It would also be desirable to improve the processing qualities of an SBR base bubble gum by addition of another gum base to the bubble gum that makes the gum easier to process.